Image sensors including channel stop regions surrounding photodiodes and methods of fabricating the same

Abstract

Image sensors are provided. In the image sensor, an area of a device isolation layer may be reduced and elements may be isolated from each other by a channel stop region extending between the photoelectric conversion region and the device isolation layer, such that a dark current property of the image sensor may be improved.

What is claimed is: 
     
       1. An image sensor comprising:
 a substrate including a plurality of pixel regions; 
 a photoelectric converting part in the substrate in each of the pixel regions; 
 a channel stop region surrounding a portion of the photoelectric converting part, in plan view; 
 a pixel voltage applying region spaced apart from the photoelectric converting part; and 
 a first device isolation layer adjacent to one sidewall of the pixel voltage applying region, the first device isolation layer spaced apart from a sidewall of the photoelectric converting part, 
 wherein the channel stop region is disposed between the pixel voltage applying region and the photoelectric converting part and between the first device isolation layer and the photoelectric converting part. 
 
     
     
       2. The image sensor of  claim 1 , further comprising:
 a transfer gate on the substrate at a side of the photoelectric converting part in each of the pixel regions; 
 a floating diffusion region adjacent to a side of the transfer gate and spaced apart from the photoelectric converting part in each of the pixel regions; 
 a reset gate adjacent to the floating diffusion region and spaced apart from the transfer gate in each of the pixel regions: and 
 a reset drain region adjacent to the reset gate and spaced apart from the floating diffusion region in each of the pixel regions, 
 wherein the reset drain region is the pixel voltage applying region; and 
 wherein the first device isolation layer is adjacent to the reset drain region. 
 
     
     
       3. The image sensor of  claim 1 , further comprising:
 a P-type dopant region and an N-type dopant region in each of the pixel regions and adjacent to each other; and 
 a second device isolation layer between the P-type dopant region and the N-type dopant region adjacent to each other, the second device isolation layer separating a junction between the P-type and N-type dopant regions. 
 
     
     
       4. The image sensor of  claim 1 , wherein the first device isolation layer is absent between the photoelectric converting parts adjacent to each other in one direction. 
     
     
       5. The image sensor of  claim 2 , wherein the first device isolation layer is between the floating diffusion region in one pixel region and the reset drain region in another pixel region adjacent to the one pixel region. 
     
     
       6. The image sensor of  claim 2 , wherein the first device isolation layer is absent in at least one of a region between the reset drain region and the photoelectric converting part and a region between the reset gate and the photoelectric converting part in a plan view. 
     
     
       7. The image sensor of  claim 3 , wherein the P-type dopant region has a dopant concentration greater than that of the substrate, and wherein the N-type dopant region has a dopant concentration greater than that of the photoelectric converting part. 
     
     
       8. An image sensor comprising:
 a substrate including a plurality of pixel regions; 
 a photoelectric converting part in the substrate in each of the pixel regions; 
 a channel stop region extending along a periphery of the photoelectric converting part; 
 a pixel voltage applying region spaced apart from the photoelectric converting part with the channel stop region interposed between the pixel voltage applying region and the photoelectric converting part; 
 a first device isolation layer adjacent to one sidewall of the pixel voltage applying region, the first device isolation layer spaced apart from the photoelectric converting part with the channel stop region interposed between the first device isolation layer and the photoelectric converting part; 
 a selection gate spaced apart from the photoelectric converting part in each of the pixel regions; 
 a source follower gate spaced apart from both the photoelectric converting part and the selection gate in each of the pixel regions; 
 a selection source region adjacent to the selection gate and spaced apart from both the source follower gate and the photoelectric converting part in each of the pixel regions; and 
 a source follower drain region adjacent to the source follower gate and spaced apart from both the selection gate and the photoelectric converting part in each of the pixel regions, 
 wherein the source follower drain region is the pixel voltage applying region; and 
 wherein the first device isolation layer is adjacent to the source follower drain region. 
 
     
     
       9. The image sensor of  claim 8 , further comprising:
 a second device isolation layer adjacent to the selection source region and spaced apart from the first device isolation layer. 
 
     
     
       10. The image sensor of  claim 8 , wherein the second device isolation layer is between the selection source region in one pixel region and the source follower drain region in another pixel region adjacent to the one pixel region. 
     
     
       11. The image sensor of  claim 8 , wherein the first device isolation layer is absent in at least one of a region between the selection source region and the photoelectric converting part, a region between the selection gate and the photoelectric converting part, a region between the source follower gate and the photoelectric converting part, and a region between the source follower drain region and the photoelectric converting part in a plan view. 
     
     
       12. The image sensor of  claim 10 , further comprising:
 a ground region between the selection source region in the one pixel region and the source follower drain region in the another pixel region adjacent to the one pixel region, 
 wherein the second device isolation layer is between the selection source region in the one pixel region and the ground region; and 
 wherein the first device isolation layer is between the ground region and the source follower drain region in the another pixel region adjacent to the one pixel region. 
 
     
     
       13. An image sensor, comprising:
 a substrate including a photoelectric conversion region therein comprising a first conductivity type; 
 a device isolation region comprising an insulating material layer in the substrate adjacent a boundary of the photoelectric conversion region; and 
 a channel stop region of the first conductivity type in the substrate extending between the boundary of the photoelectric conversion region and the device isolation region and along a periphery of the photoelectric conversion region, the channel stop region having a higher dopant concentration than the substrate, wherein:
 the photoelectric conversion region comprises a first photodiode, and a boundary between the first photodiode and a second photodiode in the substrate adjacent the first photodiode includes the channel stop region and is free of the device isolation region; or 
 the substrate further includes a floating diffusion region therein adjacent the photoelectric conversion region, and the device isolation region separates the floating diffusion region from a transistor drain region corresponding to a neighboring pixel region. 
 
 
     
     
       14. The image sensor of  claim 13 , wherein a boundary between the photoelectric conversion region and a portion of the substrate to which a pixel voltage is applied includes the channel stop region and is free of the device isolation region. 
     
     
       15. The image sensor of  claim 13 , wherein the channel stop region extends into the substrate from a surface thereof to a depth beyond the photoelectric conversion region. 
     
     
       16. The image sensor of  claim 14 , wherein the portion of the substrate to which the pixel voltage is applied comprises a drain region of a transistor of the image sensor. 
     
     
       17. The image sensor of  claim 16 , wherein the device isolation region separates the drain region from a ground region of the substrate having a conductivity type opposite thereto.